A silly idea: build a bike completely from donated bits, and get as many people to ride it as far as possible.
The yACF bike
How about each person who rides it must replace at least one part (preferably a part that hasn't yet been replaced.)
So it would start as a skip special in Lunnon and by the time it has toured the country it would come back a
changed man reformed character.
So we start off with an abandoned but just about rideable heap somewhere...
..d